1. Technical Field
The present invention relates to a functional liquid supply apparatus which supplies liquid droplets to a functional liquid droplet ejection heads of a liquid droplet ejection apparatus, a liquid droplet ejection apparatus, a method of manufacturing an electro-optical apparatus, an electro-optical apparatus and an electronic apparatus.
2. Related Art
Conventionally, as this kind of a functional liquid supply apparatus, there is known the functional liquid supply apparatus having: sub tanks which store functional liquid supplied to functional liquid droplet ejection heads; a single main tank which replenishes the functional liquid to the sub tanks; ink tubes which connect the main tank with the sub tanks; and a liquid feeding device. The liquid feeding device is constructed by pumps and valves and the like, feeds the functional liquid between each of the tanks through the ink tubes, and controls the liquid to be fed. JP A-1999-42771 is an example of related art. When the functional liquid is ejected from the functional liquid droplet ejection heads and the functional liquid stored in the sub tank reduces, the functional liquid is replenished from the main tank to the sub tanks.
However, in such the functional liquid supply apparatus described above, in some cases, it is necessary to change main tanks when the functional liquid reduces therein at a state that a replenishment signal from the sub tanks is received. In this case, when a plotting process is continued, the functional liquid in the sub tanks is empty and the functional liquid droplet ejection heads may be in an idle ejection. Therefore, it is necessary to stop the plotting process and to change main tanks. In other words, in a single main tank construction, when the main tank needs to be changed, the plotting process must be stopped, leading to a lower productivity.